Battery pack and powered device

Abstract

The application discloses a battery pack and a power utilization device, and relates to the technical field of energy equipment. The battery pack comprises a box frame, the inside of the box frame is hollow, and the box frame has two opposite open ends; a battery cell assembly is accommodated in the inside of the box frame; a top cover plate is connected with the box frame and closes one of the open ends; a first cold plate is located between the battery cell assembly and the top cover plate; a bottom guard plate is connected with the box frame and closes the other open end; a second cold plate is located between the battery cell assembly and the bottom guard plate; and a buffer assembly has a part located between the top cover plate and the battery cell assembly and a part located between the battery cell assembly and the bottom guard plate. The battery pack and the power utilization device disclosed by the application have good impact resistance at the bottom and the top, and thus the safety is improved.

Description

Technical Field

[0001] This application relates to the field of energy equipment technology, specifically to a battery pack and an electrical device. Background Technology

[0002] Most new energy vehicles typically have their battery systems located in the middle of the vehicle chassis or under the floor, very close to the ground. Since the bottom and top of the battery pack may be subjected to impacts during actual road driving, such as from speed bumps, stones, or other obstacles, high protection requirements are placed on the top and bottom of the battery pack.

[0003] In related technologies, the bottom and top structures of vehicle battery packs are typically designed with thicker reinforcements or have added ribs to increase structural strength. However, this approach cannot effectively resist top and top ball impacts. In the event of a bottom or top ball impact, the bottom and top of the battery cell may experience deformation exceeding 15%, leading to thermal runaway of the cell. Utility Model Content

[0004] In view of this, this application provides a battery pack and an electrical device, wherein the bottom and top of the battery pack have good impact resistance, thereby improving the safety of the battery pack.

[0005] The specific technical solution adopted in this application is as follows:

[0006] One embodiment of this application provides a battery pack, the battery pack comprising:

[0007] A box frame, wherein the box frame is hollow inside and has two opposite open ends;

[0008] The battery cell assembly is housed inside the housing frame;

[0009] A top cover plate, connected to the box frame and closing one of the open ends;

[0010] The first cold plate is located between the battery cell assembly and the top cover plate;

[0011] The bottom protective plate is connected to the box frame and closes the other open end;

[0012] The second cold plate is located between the battery cell assembly and the bottom protective plate;

[0013] A buffer assembly having a portion located between the top cover and the cell assembly, and a portion located between the cell assembly and the bottom cover.

[0014] Optionally, the buffer assembly includes at least one of a first buffer layer and a second buffer layer, wherein the first buffer layer is located between the top cover plate and the first cold plate, and the second buffer layer is located between the first cold plate and the cell assembly;

[0015] Wherein, the thickness of the first buffer layer is not less than the thickness of the top cover plate, and the thickness of the second buffer layer is not less than the thickness of the first buffer layer.

[0016] Optionally, the first buffer layer is foam, and the second buffer layer is a thermally conductive adhesive layer.

[0017] Optionally, the thickness of the top cover plate is not less than 1.5 mm; and / or,

[0018] The thickness of the first buffer layer is not less than 2 mm; and / or,

[0019] The thickness of the second buffer layer is not less than 3 mm.

[0020] Optionally, the battery pack further includes an integrated busbar CCS bracket located between the first cold plate and the cell assembly. The CCS bracket is provided with a plurality of protrusions that protrude toward the first cold plate at intervals. The CCS bracket can contact and cooperate with the first cold plate through the plurality of protrusions.

[0021] The battery cell assembly includes multiple battery cell plates, and the contact positions of the multiple battery cell plates with the CCS bracket are respectively located within the intervals between the multiple boss portions, wherein the second buffer layer is located between the multiple battery cell plates and the first cold plate.

[0022] Optionally, the second buffer layer is located between the CCS bracket and the first cold plate, and at least a portion of the second buffer layer is located within the interval between the plurality of bosses.

[0023] Optionally, a rib is formed on the top cover plate that protrudes toward the first buffer layer, and on the side of the top cover plate away from the first buffer layer, the rib is recessed relative to other parts of the top cover plate;

[0024] The top cover plate contacts the first buffer layer through the rib portion.

[0025] Optionally, the rib portion includes a plurality of first ribs and a plurality of second ribs, the plurality of first ribs being spaced apart and arranged in parallel, each first rib extending along a first direction, the first direction being inclined relative to the length and width directions of the top cover plate; the plurality of second ribs being spaced apart and arranged in parallel, each second rib extending along a second direction, the second direction being inclined relative to the length and width directions of the top cover plate, wherein the plurality of first ribs and the plurality of second ribs intersect.

[0026] Optionally, the buffer assembly includes at least one of a third buffer layer and a fourth buffer layer, wherein the third buffer layer is located between the cell assembly and the second cold plate, and the fourth buffer layer is located between the second cold plate and the bottom protective plate;

[0027] The thickness of the fourth buffer layer is not less than the thickness of the bottom protective plate.

[0028] Optionally, the third buffer layer is a thermally conductive adhesive layer, and the fourth buffer layer is foam.

[0029] Optionally, the thickness of the third buffer layer is not less than 1 mm; and / or,

[0030] The thickness of the fourth buffer layer is not less than 2 mm; and / or,

[0031] The thickness of the bottom protective plate is not less than 1 mm.

[0032] Optionally, the first cold plate and the second cold plate are welded to the box frame respectively; and / or,

[0033] At least one of the first cold plate and the second cold plate is a cold plate made of extruded profile.

[0034] Optionally, the box frame includes multiple sealing beams and two expansion beams;

[0035] The plurality of sealing beams are connected sequentially along the circumference of the box frame and are sealed to the top cover plate and the bottom protective plate;

[0036] The two expansion beams are respectively connected to the adjacent beam walls of two of the plurality of sealing beams that are positioned opposite each other, wherein the battery cell assembly is located between the two expansion beams.

[0037] Optionally, the thickness of the expansion beam is not less than 25 mm.

[0038] Another aspect of this application provides an electrical device, which includes a device body and the battery pack described in the previous aspect, wherein the device body is powered by the battery pack.

[0039] The battery pack provided in this application embodiment has buffer components between the top cover and the cell assembly, and between the bottom cover and the cell assembly. Therefore, when the top or bottom of the battery pack is impacted by an external object, the buffer components can absorb the energy of the impact force, thereby reducing or even eliminating the impact force that the cell assembly needs to withstand. This reduces the probability of severe deformation of the cell assembly, thereby avoiding battery thermal runaway and improving safety. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the appearance of a battery pack provided in an embodiment of this application;

[0042] Figure 2 yes Figure 1 Exploded view of the battery pack shown;

[0043] Figure 3 This is a schematic diagram of the CCS bracket in the battery pack provided in the embodiments of this application;

[0044] Figure 4 yes Figure 3 Enlarged view of point A in the middle;

[0045] Figure 5 It is along Figure 1 A schematic diagram of the cross-sectional structure obtained by cutting along line AA in the middle;

[0046] Figure 6 yes Figure 5 Enlarged view of point B in the middle;

[0047] Figure 7 This is a cross-sectional structural diagram of the top cover plate in the battery pack provided in the embodiments of this application;

[0048] Figure 8 This is a schematic diagram of the connection between the battery pack frame and the first cold plate provided in an embodiment of this application;

[0049] Figure 9 This is a schematic diagram showing the connection between the battery pack frame and the second cold plate in an embodiment of this application;

[0050] Figure 10 This is a schematic diagram of the structure of the battery pack frame provided in the embodiments of this application.

[0051] Figure label:

[0052] 1. Box frame; 11. Open end; 12. Sealed beam; 13. Expansion beam;

[0053] 2. Battery cell assembly; 21. Battery cell plate; 22. Battery cell shoulder;

[0054] 3. Top cover plate; 31. First rib; 32. Second rib;

[0055] 4. First cold plate;

[0056] 5. Bottom protective plate;

[0057] 6. Second cold plate;

[0058] 7. Buffer component; 71. First buffer layer; 72. Second buffer layer; 73. Third buffer layer; 74. Fourth buffer layer;

[0059] 8. CCS bracket; 81. Boss part.

[0060] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0061] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0062] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0063] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0064] This application provides a battery pack, such as... Figure 1 and Figure 2 As shown, the battery pack includes a frame 1, a cell assembly 2, a top cover 3, a first cold plate 4, a second cold plate 6, a bottom protective plate 5, and a buffer assembly 7.

[0065] The housing 1 is a hollow, annular structure with two opposing open ends 11 along its axial direction. The interior of the housing 1 communicates with the outside through these two open ends 11. The battery cell assembly 2 is housed inside the housing 1. The housing 1 is a rigid structure, providing structural support and protection to ensure that the battery cell assembly 2 will not deform or be damaged due to impact or compression during use. Optionally, the housing 1 is typically made of a high-strength material, such as aluminum alloy, to improve its impact resistance and durability.

[0066] Cell assembly 2 is the core component of the battery pack. Typically, cell assembly 2 consists of multiple cells, which are used to store and release electrical energy.

[0067] The top cover 3 is located at the top of the battery pack and is connected to one open end 11 of the frame 1, thereby sealing the open end 11. The connection between the top cover 3 and the frame 1 is typically sealed; for example, a sealant layer can be placed between the top cover 3 and the frame 1 to ensure the airtightness of the battery pack, preventing dust, moisture, and air from entering and extending the battery's lifespan. Simultaneously, the top cover 3 also provides resistance to mechanical impact, protecting the cell assembly 2 and preventing deformation.

[0068] The bottom protective plate 5 is located at the bottom of the battery pack and is connected to another open end 11 of the frame 1, thereby sealing the open end 11. The bottom protective plate 5 and the frame 1 are also sealed together; for example, a sealant layer can be provided between the bottom protective plate 5 and the frame 1 to ensure the internal sealing of the battery pack, prevent dust, moisture, and air from entering, and extend the battery's lifespan. The bottom protective plate 5 protects the battery pack from damage caused by bottom impacts. The bottom protective plate 5 is typically made of high-strength materials and may be equipped with a pressure relief chamber or protective layer to absorb impact energy and disperse pressure, thereby protecting the cell assembly 2 from direct impacts.

[0069] A first cold plate 4 and a second cold plate 6 are located between the battery cell assembly 2 and the top cover plate 3, and the second cold plate 6 is located between the battery cell assembly 2 and the bottom cover plate 5. The cold plates serve a heat dissipation function, employing thermally conductive materials or a liquid cooling system to effectively transfer and dissipate the heat generated by the battery cell assembly 2. For example, a liquid cooling plate can pump coolant through internal channels to achieve efficient heat dissipation, helping to maintain the battery cell assembly 2 at a suitable operating temperature. Furthermore, the cold plates can also serve as structural supports, providing mechanical protection for the battery cell assembly 2. In some embodiments, at least one of the first cold plate 4 and the second cold plate 6 is a cold plate made of extruded profile. Extruded cold plates typically have high strength, high dimensional accuracy, and stable quality.

[0070] The buffer assembly 7 is used to cushion the impact when the battery pack is subjected to an impact, absorbing the impact energy and protecting the cell assembly 2 from deformation. The buffer assembly 7 comprises multiple interconnected or independent parts. One part of the buffer assembly 7 can be disposed between the top cover plate 3 and the cell assembly 2, for example, between the top cover plate 3 and the first cold plate 4, and / or between the first cold plate 4 and the cell assembly 2. Another part of the buffer assembly 7 can be disposed between the cell assembly 2 and the bottom protective plate 5, for example, between the cell assembly 2 and the second cold plate 6, and / or between the second cold plate 6 and the bottom protective plate 5.

[0071] The battery pack provided in this application embodiment has a buffer component 7 between the top cover plate 3 and the cell assembly 2, and between the bottom cover plate 5 and the cell assembly 2. Therefore, when the top or bottom of the battery pack is impacted by an external object, the buffer component 7 can absorb the energy of the impact force, thereby reducing or even eliminating the impact force that the cell assembly 2 needs to withstand. This reduces the probability of severe deformation of the cell assembly 2, thereby avoiding battery thermal runaway and improving safety.

[0072] The top cover 3 of the battery pack provided in this application embodiment is typically made of aluminum alloy or steel, taking into account factors such as lightweight, strength, thermal conductivity, corrosion resistance, and cost. The aluminum alloy top cover 3 meets the lightweight requirement and has advantages such as moderate strength, good thermal conductivity, and corrosion resistance. For scenarios requiring impact resistance or load-bearing capacity, such as applications in commercial vehicles, the top cover 3 of the battery pack can be made of steel, thus giving it high strength. Of course, the top cover 3 can also be made of other materials, such as composite materials or magnesium alloys; those skilled in the art can select the material of the top cover 3 according to actual needs.

[0073] Optionally, the thickness of the top cover plate 3 is not less than 1.5mm. For example, the thickness of the top cover plate 3 can be 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc. It should be understood that the thicker the top cover plate 3, the better its strength, but the greater its weight and the higher the overall height of the battery pack. Taking all factors into consideration, the thickness of the top cover plate 3 can be set in the range of 1.5-3mm.

[0074] In some embodiments, reinforcing ribs may be provided on the top cover plate 3 to meet the requirements of improving the impact resistance and compressive strength of the top cover plate 3. For example... Figure 7 As shown, a rib 30 protruding toward the buffer assembly 7 is formed on the top cover plate 3. Optionally, the rib 30 is integrally formed with other parts of the top cover plate 3, thereby ensuring that the top cover plate 3 has high structural strength and is easy to process.

[0075] It should be understood that the rib portion 30 "protrudes toward the buffer assembly 7 (e.g., the first buffer layer 71)" means that when viewed from the side of the top cover plate 3 away from the first buffer layer 71, the rib portion 30 is recessed relative to the other parts of the top cover plate 3; when viewed from the side of the top cover plate 3 close to the first buffer layer 71, the rib portion 30 protrudes relative to the other parts of the top cover plate 3.

[0076] The top cover plate 3 contacts the first buffer layer 71 through the rib 30, reducing the contact area between the top cover plate 3 and the first buffer layer 71. When the top of the battery pack is impacted, such as in a top drop ball test, the rib 30 can quickly guide and disperse the impact load at the drop point, avoiding local stress concentration at the drop point. Moreover, the rib 30 also forms a buffer space between the drop point on the top cover plate 3 and the first buffer layer 71, allowing the rib 30 to dissipate impact energy through its own minor deformation (such as bending, shearing, etc.), reducing the impact load on the first buffer layer 71. In other words, in addition to increasing the structural strength of the top cover plate 3, the rib 30 also forms a buffer space between the rest of the top cover plate 3 and the first buffer layer 71, which facilitates the absorption and dissipation of impact energy, thereby improving the impact resistance of the top cover plate 3 and further reducing the damage to the battery pack from top impacts.

[0077] like Figure 7 As shown, the rib portion 30 may include multiple first ribs 31 and multiple second ribs 32. The multiple first ribs 31 are spaced apart and arranged in parallel. Each first rib 31 extends along a first direction, which is inclined relative to the length direction of the top cover plate 3 and also inclined relative to the width direction of the top cover plate 3. The multiple second ribs 32 are spaced apart and arranged in parallel. Each first rib 31 extends along a second direction, which is inclined relative to the length direction of the top cover plate 3 and also inclined relative to the width direction of the top cover plate 3. The multiple first ribs 31 and the multiple second ribs 32 have intersecting portions.

[0078] Optionally, the angle between the first direction and the width direction of the top cover plate 3 is 20°-60°, and the angle between the second direction and the width direction of the top cover plate 3 is 120°-160°.

[0079] By arranging the first rib 31 and the second rib 32 at an angle, additional support can be provided in multiple directions, thereby improving the overall structural strength and bending resistance of the top cover plate 3. This helps to distribute stress more evenly in the structure, thus better coping with complex load distribution. This avoids the stress concentration problem that may occur when the top cover plate 3 is arranged parallel to the length and width directions.

[0080] In some embodiments of this application, such as Figure 2As shown, the buffer component 7 may include at least one of a first buffer layer 71 and a second buffer layer 72.

[0081] The first buffer layer 71 is located between the top cover plate 3 and the first cold plate 4, and the thickness of the first buffer layer 71 is not less than the thickness of the top cover plate 3.

[0082] Optionally, when the top cover plate 3 is made of steel plate with a thickness of not less than 1.5 mm, the thickness of the first buffer layer 71 is not less than 2 mm, for example, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, etc.

[0083] By setting the first buffer layer 71, the distance between the top cover plate 3 and the first cold plate 4 is greater than or equal to 2mm. Therefore, when the impact energy from the top is transmitted downward through the top cover plate 3, the energy can be absorbed and dissipated through the first buffer layer 71, thereby further protecting the battery cell assembly 2 and reducing the probability of it being damaged.

[0084] Optionally, the first buffer layer 71 can be foam. Foam has advantages such as good cushioning and shock absorption performance, low density, light weight, good abrasion resistance, and low cost.

[0085] The second buffer layer 72 is located between the first cold plate 4 and the cell assembly 2, and the thickness of the second buffer layer 72 is not less than the thickness of the first buffer layer 71.

[0086] Optionally, when the thickness of the first buffer layer 71 is not less than 2 mm, the thickness of the second buffer layer 72 is not less than 3 mm, for example, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, etc.

[0087] By setting the second buffer layer 72, the distance between the first cold plate 4 and the battery cell assembly 2 is greater than or equal to 3mm. Therefore, when the top impact energy is transmitted downward through the first cold plate 4, the energy can be absorbed and dissipated through the second buffer layer 72, thereby further protecting the battery cell assembly 2 and reducing the probability of it being damaged.

[0088] Optionally, thermally conductive adhesive can be filled between the first cold plate 4 and the battery cell assembly 2 to form a thermally conductive adhesive layer. This thermally conductive adhesive layer can serve as a second buffer layer 72. Since the first cold plate 4 needs to dissipate heat and cool the battery cell assembly 2, thermally conductive adhesive can be used to fill the space between the first cold plate 4 and the battery cell assembly 2 to ensure heat dissipation, thereby enabling the thermally conductive adhesive layer to simultaneously perform the functions of heat conduction and heat dissipation as well as buffering and shock absorption.

[0089] In some embodiments of this application, such as Figure 2As shown, the battery pack also includes an integrated busbar (CCS, Cells Contact System) bracket located between the first cold plate 4 and the cell assembly 2. The CCS bracket 8 is mainly used for the integrated series connection and fixation of the battery cells. Figure 3 and Figure 4 As shown, the CCS bracket 8 has multiple protrusions 81 spaced apart and projecting towards the first cold plate 4. (See also...) Figure 5 and Figure 6 The CCS bracket 8 can contact and engage with the first cold plate 4 through multiple protrusions 81.

[0090] See also Figure 6 The battery cell assembly 2 includes multiple battery cell plates 21. The battery cell plates 21 are typically made of copper or aluminum and are connected to the battery cell terminals by welding or pressing, while also being electrically connected to an external circuit (such as a battery management system, BMS) to collect and conduct the current from individual cells to the external circuit.

[0091] In the embodiments of this application, such as Figure 6 As shown, multiple battery cells 21 are in contact with the CCS bracket 8, and each contact position is located within the interval between multiple bosses 81.

[0092] When the top of the battery pack is impacted, the impact force is transmitted sequentially through the top cover plate 3, the first buffer layer 71, and the first cold plate 4 to the protrusion 81 of the CCS bracket 8, and then continues to be transmitted downwards from the protrusion 81. Since the multiple battery cells 21 are located within the intervals between the multiple protrusions 81, the impact force is minimal or only slightly applied to the battery cells 21, thus avoiding loosening or breakage of the connection points and short circuits due to misalignment of the positive and negative terminals caused by the impact on the battery cells 21.

[0093] In some embodiments, the second buffer layer 72 may be located between the plurality of battery cells 21 and the first cold plate 4 to further protect the battery cells 21 and minimize the impact on the battery cells 21.

[0094] like Figure 6 As shown, in one example, the second buffer layer 72 can be disposed between the CCS bracket 8 and the first cold plate 4, and at least part of the second buffer layer 72 fills the gap between the plurality of bosses 81, so that each cell bar 21 has a portion of the second buffer layer 72 on the side near the first cold plate 4, thus achieving shock absorption protection for each cell bar 21.

[0095] It should be noted that "at least a portion of the second buffer layer 72 fills the gaps between the plurality of protrusions 81" can include the case where the entire second buffer layer 72 is located within the gaps between adjacent protrusions 81, so that the top surfaces of the plurality of protrusions 81 are in direct contact with the first cold plate 4; or it can include the case where a portion of the second buffer layer 72 is located within the gaps between adjacent protrusions 81, and another portion of the second buffer layer 72 covers the top surfaces of the protrusions 81, so that at least a portion of the protrusions 81 are in indirect contact with the first cold plate 4 through the second buffer layer 72. Here, the top surface of the protrusion 81 refers to the surface near the first cold plate 41.

[0096] In some embodiments of this application, a plurality of bosses 81 may contact and engage with the cell shoulders 22 of a plurality of cells in the cell assembly 2, thereby transmitting the impact force to the cell shoulders 22.

[0097] like Figure 6 As shown, multiple protrusions 81 have a first orthographic projection on the surface of the first cold plate 4, and multiple battery cells in the battery cell assembly 2 have a second orthographic projection on the surface of the first cold plate 4. The terminals (not shown in the figure) and explosion-proof valves (not shown in the figure) of multiple battery cells in the battery cell assembly 2 have a third orthographic projection on the surface of the first cold plate 4. The first orthographic projection is located within or coincides with the second orthographic projection; the first orthographic projection is located outside the third orthographic projection.

[0098] This means that along the height direction of the battery (i.e., the direction in which the top cover plate 3 and the bottom cover plate 5 are positioned opposite each other), the multiple protrusions 81 of the CCS bracket 8 correspond to the positions of the cell shoulders 22 of the multiple battery cells, and avoid the cell terminals and explosion-proof valves. Thus, when an impact force is transmitted downwards through the protrusions 81, it will act on the cell shoulders 22, but not on the cell terminals and explosion-proof valves. Since the cell shoulders 22 are typically of high strength, they can withstand and resist impact forces, preventing thermal runaway and explosion caused by impact to the cell terminals and explosion-proof valves.

[0099] To improve the impact resistance of the bottom of the battery pack, the bottom protective plate 5 can be designed in a similar manner to the top cover 3. For example, the bottom protective plate 5 can be made of a high-strength material, or its thickness can be increased, or reinforcing ribs can be added to the bottom protective plate 5.

[0100] In some embodiments, taking into account factors such as lightweight, strength, thermal conductivity, corrosion resistance, and cost, the bottom guard plate 5 can be made of aluminum alloy or steel. The advantages and applicable scenarios of aluminum alloy and steel have been mentioned above and will not be repeated here.

[0101] Optionally, the thickness of the bottom protective plate 5 is not less than 1 mm. For example, the thickness of the bottom protective plate 5 can be 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc. It should be understood that the thicker the bottom protective plate 5, the better its strength, but the greater the weight and the higher the overall height of the battery pack. Taking all factors into consideration, the thickness of the bottom protective plate 5 can be set in the range of 1-3 mm.

[0102] In some embodiments of this application, the thickness of the bottom cover plate 5 is less than the thickness of the top cover plate 3, because in addition to mechanical impact, the top cover plate 3 may face higher temperature changes and thermal shock risks during use.

[0103] In some embodiments, reinforcing ribs may be provided on the bottom protective plate 5 to meet the requirements of improving the impact resistance and compressive strength of the bottom protective plate 5. Exemplarily, the arrangement and style of the reinforcing ribs on the bottom protective plate 5 may be the same as or similar to the arrangement and style of the first protruding rib 31 and the second protruding rib 32 on the top cover plate 3.

[0104] In some embodiments of this application, such as Figure 2 As shown, the buffer assembly 7 also includes at least one of a third buffer layer 73 and a fourth buffer layer 74.

[0105] The fourth buffer layer 74 is located between the second cold plate 6 and the bottom protective plate 5, and the thickness of the fourth buffer layer 74 is not less than the thickness of the bottom protective plate 5.

[0106] Optionally, when the bottom guard plate 5 is made of steel plate with a thickness of not less than 1 mm, the thickness of the fourth buffer layer 74 is not less than 2 mm, for example, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, etc.

[0107] By setting the fourth buffer layer 74, the distance between the bottom protective plate 5 and the second cold plate 6 is greater than or equal to 1mm. Therefore, when the impact energy at the bottom of the battery pack is transmitted upward through the bottom protective plate 5, the energy can be absorbed and dissipated through the fourth buffer layer 74, thereby further protecting the cell assembly 2 and reducing the probability of it being damaged.

[0108] Optionally, the fourth buffer layer 74 can be foam. Foam has advantages such as good cushioning and shock absorption performance, low density, light weight, good abrasion resistance, and low cost.

[0109] The third buffer layer 73 is located between the cell assembly 2 and the second cold plate 6. Optionally, the thickness of the third buffer layer 73 is not less than 1 mm, for example, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc.

[0110] By setting a third buffer layer 73, the distance between the battery cell assembly 2 and the second cold plate 6 is greater than or equal to 1mm. When the impact energy at the second cold plate 6 is transmitted upward, the energy can be absorbed and dissipated through the third buffer layer 73, thereby further protecting the battery cell assembly 2 and reducing the probability of it being damaged.

[0111] Optionally, the third buffer layer 73 is a thermally conductive adhesive layer. Since the second cold plate 6 needs to dissipate heat and cool the battery cell assembly 2, thermally conductive adhesive can be used to fill the space between the second cold plate 6 and the battery cell assembly 2 to ensure heat dissipation. This allows the thermally conductive adhesive layer to simultaneously perform the functions of heat conduction and heat dissipation, as well as buffering and shock absorption.

[0112] In some embodiments of this application, such as Figure 8 and Figure 9 As shown, the first cold plate 4 and the second cold plate 6 are welded to the frame 1 respectively. In this way, when the top impact force of the battery pack is transmitted to the first cold plate 4, or the bottom impact force is transmitted to the second cold plate 6, part of the impact force can act on the high-strength frame 1 through the first cold plate 4 or the second cold plate 6, thereby reducing the probability of impact damage to the battery cell assembly 2.

[0113] In some embodiments of this application, such as Figure 10 As shown, the housing frame 1 includes multiple sealing beams 12, which are connected sequentially along the circumference of the housing frame 1 and are sealed to the top cover plate 3 and the bottom protective plate 5. The housing frame 1 of the battery pack is sealed to the bottom protective plate 5 of the top cover plate 3 in the circumference through the sealing beams 12, which ensures the sealing performance inside the battery pack, thereby ensuring the safety, performance and lifespan of the battery cell assembly 2.

[0114] In some embodiments, the sealing beam 12 and the top cover plate 3 are sealed with sealant (not shown in the figure), and / or the sealing beam 12 and the bottom cover plate 5 are sealed with sealant (not shown in the figure).

[0115] Sealing with sealant is a simple process, and the resulting high-strength sealing layer effectively prevents liquid leakage and the intrusion of external dust and impurities. Furthermore, the sealant possesses excellent adhesion and chemical resistance, providing strong bonding in complex shapes and irregular structures while withstanding mechanical stress.

[0116] Optionally, the box frame 1 may have an annular groove on the top of the multiple sealing beams 12, and the annular groove is filled with sealant; the top cover plate 3 may have an annular protrusion on the side near the box frame 1, which is embedded in and bonded to the groove wall of the annular groove with sealant, thereby ensuring good sealing performance at the connection between the box frame 1 and the top cover plate 3.

[0117] In the embodiments of this application, such as Figure 10As shown, the box frame 1 also includes two expansion beams 13, which are connected to the adjacent beam walls of two of the multiple sealing beams 12 that are positioned opposite each other.

[0118] like Figure 2 As shown, the battery cell assembly 2 is located between two expansion beams 13. The battery cell assembly 2 expands during charging and discharging. The expansion beams 13 are used to resist the expansion deformation of the battery cell assembly 2. By dispersing the expansion force generated by the battery cell assembly 2, the direct impact on the frame 1 can be reduced, the risk of deformation of the frame 1 can be reduced, thereby protecting the stability and safety of the internal structure of the battery pack.

[0119] In addition, the design of the expansion beam 13 can enhance the overall structural strength and stability of the battery pack, prevent the connectors from loosening or falling off due to cell expansion, and further improve the safety of the battery pack.

[0120] Optionally, the thickness of the expansion beam 13 is not less than 25 mm. Exemplarily, the thickness of the expansion beam 13 ranges from 25 to 40 mm, such as 25 mm, 30 mm, 35 mm, 40 mm, etc. Expansion beams 13 within this thickness range can meet the requirements for structural strength and lightweighting.

[0121] In some embodiments of this application, the battery pack uses a top cover plate 3 with a thickness greater than 1.5 mm, and a CCS bracket 8 with a boss portion 81 that can transfer impact energy to the cell shoulder portion 22. The distance between the top cover plate 3 and the first cold plate 4 is greater than 2 mm and is filled with a first buffer layer 71. The distance between the cell bar 21 and the first cold plate 4 is greater than 3 mm and is filled with a second buffer layer 72. Meanwhile, the first cold plate 4 is made of high-strength extruded cold plate, which enables the battery pack to withstand a top drop ball test with an impact energy of not less than 120 J.

[0122] In some embodiments of this application, the battery pack uses a bottom protective plate 5 with a thickness greater than 1 mm, and the distance between the bottom protective plate 5 and the second cold plate 6 is greater than 2 mm and filled with a fourth buffer layer 74. The distance between the cell assembly 2 and the second cold plate 6 is greater than 1 mm and filled with a third buffer layer 73. Meanwhile, the second cold plate 6 is made of high-strength extruded cold plate and is welded to the box frame 1, which enables the battery pack to withstand bottom ball impact tests with an impact energy of not less than 120J. In summary, the battery pack provided in this application embodiment has a first buffer layer 71 between the top cover plate 3 and the first cold plate 4, a second buffer layer 72 between the first cold plate 4 and the cell assembly 2, a fourth buffer layer 74 between the bottom cover plate 5 and the second cold plate 6, and a third buffer layer 73 between the cell assembly 2 and the second cold plate 6. A boss 81 is provided on the CCS bracket 8 to contact the first cold plate 4 and to correspond to the battery shoulder. The battery cell's contact plate, terminal, and explosion-proof valve are positioned to avoid the boss 81. Therefore, when the top or bottom of the battery pack is impacted by an external object, the impact force is dissipated and absorbed by the buffer layers or dissipated through the frame 1. Even if some impact energy remains, the residual impact energy will not directly act on the cell contact plate 21, terminal, and explosion-proof valve, but will act on the stronger cell shoulder 22, thereby reducing the probability of severe deformation of the cell assembly 2, thus avoiding battery thermal runaway and improving safety.

[0123] This application also provides an electrical device, which includes a device body and a battery pack as described in the above embodiments, wherein the device body is powered by the battery pack as described in the above embodiments.

[0124] For example, the electrical equipment may be an energy storage device (such as a home or outdoor energy storage power supply), electronic products, power tools, industrial electrical equipment, new energy vehicles, electric bicycles / scooters, special vehicles and equipment, etc.

[0125] Taking a new energy vehicle (such as a pure electric vehicle or a hybrid vehicle) as an example, since the battery pack is usually installed in the middle of the vehicle's chassis or under the floor, the bottom and top of the battery pack are easily impacted by external objects during vehicle operation, leading to deformation and damage to the battery cells. In this embodiment, by improving the impact resistance of the bottom and top of the battery pack, the probability of deformation and damage to the battery cells in the battery pack is reduced, thereby avoiding battery thermal runaway, significantly improving the safety performance of the battery pack, and thus improving the safety and service life of the electrical equipment using this battery pack.

[0126] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only.

[0127] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A battery pack, characterized by, The battery pack comprises: a box frame (1) which is hollow inside and has two opposite open ends (11); a cell assembly (2) accommodated in the inside of the box frame (1); a top cover plate (3) connected with the box frame (1) and closing one of the open ends (11); a first cold plate (4) located between the cell assembly (2) and the top cover plate (3); a bottom guard plate (5) connected with the box frame (1) and closing the other open end (11); a second cold plate (6) located between the cell assembly (2) and the bottom guard plate (5); a buffer assembly (7) having a part located between the top cover plate (3) and the cell assembly (2), and a part located between the cell assembly (2) and the bottom guard plate (5).

2. The battery pack of claim 1, wherein, The buffer assembly (7) comprises at least one of a first buffer layer (71) located between the top cover plate (3) and the first cold plate (4), and a second buffer layer (72) located between the first cold plate (4) and the cell assembly (2); wherein the thickness of the first buffer layer (71) is not less than the thickness of the top cover plate (3), and the thickness of the second buffer layer (72) is not less than the thickness of the first buffer layer (71).

3. The battery pack of claim 2, wherein, The first buffer layer (71) is foam, and the second buffer layer (72) is a heat-conducting adhesive layer.

4. The battery pack of claim 2, wherein: the thickness of the top cover plate (3) is not less than 1.5 mm; and / or the thickness of the first buffer layer (71) is not less than 2 mm; and / or the thickness of the second buffer layer (72) is not less than 3 mm.

5. The battery pack of any one of claims 2-4, wherein, The battery pack further comprises an integrated CCS support (8) located between the first cold plate (4) and the cell assembly (2), the CCS support (8) being provided with a plurality of boss portions (81) protruding towards the first cold plate (4) at intervals, the CCS support (8) being capable of being in contact with the first cold plate (4) through the plurality of boss portions (81); The cell assembly (2) comprises a plurality of cell bars (21), the contact positions of the plurality of cell bars (21) with the CCS support (8) being located within the intervals between the plurality of boss portions (81), wherein the second buffer layer (72) is located between the plurality of cell bars (21) and the first cold plate (4).

6. The battery pack of claim 5, wherein, The second buffer layer (72) is located between the CCS support (8) and the first cold plate (4), and at least part of the second buffer layer (72) is located within the intervals between the plurality of boss portions (81).

7. The battery pack of claim 2, wherein, The top cover plate (3) is formed with a protruding rib portion (30) protruding towards the first buffer layer (71), the protruding rib portion (30) being recessed relative to other portions of the top cover plate (3) on the side of the top cover plate (3) away from the first buffer layer (71); The top cover plate (3) is in contact with the first buffer layer (71) through the protruding rib portion (30).

8. The battery pack of claim 7, wherein, The convex rib part (30) comprises a plurality of first convex ribs (31) and a plurality of second convex ribs (32), The plurality of first convex ribs (31) are arranged in parallel and spaced apart, and each first convex rib (31) extends in a first direction, which is inclined with respect to the length direction and the width direction of the top cover plate (3); The plurality of second convex ribs (32) are arranged in parallel and spaced apart, and each second convex rib (32) extends in a second direction, which is inclined with respect to the length direction and the width direction of the top cover plate (3); The plurality of first convex ribs (31) and the plurality of second convex ribs (32) intersect.

9. The battery pack of claim 1, wherein, The buffer assembly (7) comprises at least one of a third buffer layer (73) and a fourth buffer layer (74), the third buffer layer (73) is located between the battery cell assembly (2) and the second cold plate (6), and the fourth buffer layer (74) is located between the second cold plate (6) and the bottom guard plate (5). The thickness of the fourth buffer layer (74) is not less than the thickness of the bottom guard plate (5).

10. The battery pack of claim 9, wherein, The third buffer layer (73) is a heat-conducting adhesive layer, and the fourth buffer layer (74) is foam.

11. The battery pack of claim 9 or 10, wherein, The thickness of the third buffer layer (73) is not less than 1 mm; and / or, The thickness of the fourth buffer layer (74) is not less than 2 mm; and / or, The thickness of the bottom guard plate (5) is not less than 1 mm.

12. The battery pack of claim 1, wherein, The first cold plate (4) and the second cold plate (6) are respectively welded to the box frame (1); and / or, At least one of the first cold plate (4) and the second cold plate (6) is a cold plate made of an extruded profile.

13. The battery pack of claim 1, wherein, The box frame (1) comprises a plurality of sealing beams (12) and two expansion beams (13); The plurality of sealing beams (12) are sequentially connected along the circumference of the box frame (1) and are sealingly connected to the top cover plate (3) and the bottom guard plate (5); The two expansion beams (13) are respectively connected to the beam walls of the two sealing beams (12) that are opposite to each other in the plurality of sealing beams (12) and are close to each other, and the battery cell assembly (2) is located between the two expansion beams (13).

14. The battery pack of claim 13, wherein, The thickness of the expansion beam (13) is not less than 25 mm.

15. An electrical device, characterized by The electrical device comprises a device body and the battery pack of any one of claims 1-14, and the device body is powered by the battery pack.

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